The present invention relates to a pneumatic-hydraulic system for driving a hydraulic actuator under control of hydraulic pressure intermittently converted from pneumatic pressure.
Such a pneumatic-hydraulic system as described above is useful owing to the differing respective characteristics of pneumatic and hydraulic pressure. In conventional pneumatic-hydraulic systems it has, however, been required to provide at least two pneumatic-hydraulic converters for producing reciprocating motion of a hydraulic actuator such as a hydraulically-powered work cylinder. This results in a complicated piping arrangement and a high manufacturing cost for the system.